Back to results
US 8,804,377 B2Granted
Charge-mode control device for a resonant converter
AssigneeSTMicroelectronics S.r.l.
InventorsClaudio Adragna, Aldo Vittorio Novelli, Christian Leone Santoro
Life of this patent
Estimating the term…
Abstract
A control device for a resonant converter, the control device including a first circuit to integrate at least one signal indicating a half wave of a current circulating in a primary winding of a transformer; the first circuit is structured to generate at least a control signal of the switching circuit depending on the integrated signal. The control device includes a second circuit to impose the equality of a switching-on time period of the first and second switches.
Claims19
A circuit, comprising:
- a control circuit having:
- a set-reset flip-flop having a set input terminal, a reset input terminal, and first and second output terminals;
- a control signal generator that includes:
- an integrator circuit having first and second input terminals and configured to receive at least one input signal on the first input terminal and to generate an integrated signal;
- and
- a first comparator having a first input terminal structured to receive only the integrated signal from the integrator circuit, a second input terminal structured to receive a control voltage, and an output terminal coupled to the reset input terminal of the set-reset flip-flop, the first comparator structured to generate on the output terminal a first control signal;
- a switching control circuit that includes:
- first and second constant current generators connected in series at a common point and between a voltage source and a ground reference potential;
- a capacitor coupled between the common point and the ground reference potential;
- and
- a second comparator having a first input terminal directly connected only to the common point, a second input terminal coupled to a reference voltage source, and an output terminal coupled to the set input terminal of the set-reset flip-flop.
8 more elements
A control device for a resonant converter, the control device comprising:
- a flip-flop having first and second input terminals and first and second output terminals;
- an integrator circuit structured to receive at least one signal corresponding to a half wave of current in the resonant converter and to generate an integrated signal, the integrator circuit further including a first comparator having a first input structure to receive only the integrated signal, the first comparator further structured to generate a first control signal in response to the integrated signal and to transmit the first control signal to the first input terminal of the flip-flop;
- and
- a switching control circuit structured to impose equality of switching-on time periods of first and second switches in the resonant converter, the switching control circuit having an output terminal coupled to the second input terminal of the flip-flop and structured to transmit a second control signal on the output terminal to the second input terminal of the flip-flop.
1 more element
A resonant converter, comprising:
- at least one transformer with a primary winding and a secondary winding;
- a half bridge circuit having first and second switches coupled to a central point of the half bridge, the central point of the half bridge circuit coupled to the primary winding;
- a control device that includes:
- a flip-flop having first and second input terminals and first and second output terminals;
- an integrator circuit structured to integrate at least one signal corresponding to a half wave of current in the resonant converter and to generate an integrated signal, the integrator circuit including a first comparator having a first input structure to receive only the integrated signal and a second input structured to receive a feedback signal, the comparator further structured to generate a first control signal to the first input terminal of the flip-flop in response to a comparison of the integrated signal and the feedback signal;
- and
- a switching control circuit structured to impose equality of switching-on time periods of the first and second switches, the switching control circuit having an output terminal coupled to the second input terminal of the flip-flop.
4 more elements
A control method, comprising:
- integrating a signal corresponding to a half wave of current circulating in a primary winding of a resonant converter;
- generating a first control signal in response to the integrated signal to drive a switching circuit for the primary winding in response to the integrated signal;
- generating a second control signal that imposes an equality of a switching-on time period of first and second switches in the switching circuit by:
- generating a charge current and a discharge current of equal values;
- charging a capacitor with the charge current at a charging rate starting from an initial voltage value during a conduction time of the first switch;
- and
- discharging the capacitor with the discharge current during a conduction time of the second switch at a discharge rate that is the same as the charging rate;
- and
- opening the second switch in response to the capacitor discharging to the initial voltage value.
6 more elements
Dependencies are inferred from the claim text.